The acceleration mechanism of shock wave induced by millisecond-nanosecond combined-pulse laser on silicon  

作　　者：Jingyi LI Wei ZHANG Yu ZHOU Boshi YUAN Jixing CAI Guangyong JIN 李婧祎;张巍;周宇;苑博识;蔡继兴;金光勇(Jilin Key Laboratory of Solid-state Laser Technology and Application,School of Science,Changchun University of Science and Technology,Changchun 130022,People's Republic of China)

机构地区：[1]Jilin Key Laboratory of Solid-state Laser Technology and Application,School of Science,Changchun University of Science and Technology,Changchun 130022,People's Republic of China

出　　处：《Plasma Science and Technology》2021年第5期139-146,共8页等离子体科学和技术（英文版）

基　　金：supported by the Natural Science Foundation of Jilin Province (No. 20200201194JC);the Education Department of Jilin Province (No. JJKH20200735KJ);National Natural Science Youth Science Fund Project (No. 62005023)。

摘　　要：The velocity variation law of shock wave induced by millisecond-nanosecond combined-pulse laser has been investigated experimentally. The pulse delay and laser energy are important experimental variables. The method of laser shadowgraphy is used in the experiment.Experimental results show that when the pulse delay is 2.4 ms, the ms and ns laser energy density is 301 J cm^(-2) and 12 J cm^(-2), respectively, the velocity of shock wave is 1.09 times faster than that induced by single ns pulse laser. It is inferred that the shock wave propagates in the plasma is faster than that in air. When the ms and ns laser energy density is 414.58 and 24 J cm^(-2), the velocity of shock wave shows rising trend with pulse delay in a range of 1.4 ms>Δt> 0.8 ms. It is indicated that with the increase of ns laser energy, the laser energy absorbed by laser-supported absorption wave increases. The mechanism of inverse bremsstrahlung absorption acts with target surface absorption simultaneously during the ns laser irradiation. Thus, the phenomenon of the double shock wave is induced. The numerical results of the phenomenon were accordance with experiment. The results of this research can provide a reference for the field of laser propulsion.

关 键 词：shock wave laser-supported absorption wave plasma 

分 类 号：TN249[电子电信—物理电子学] TN304.12